The Awesome Benefits of Metformin for Women with PCOS: What Every Cyster NEEDs to Know

by | Aug 5, 2016

If you have PCOS favicon, there is a good chance you have heard of the medication metformin. However, what you may not know is why it was prescribed for you in the first place. So much of the advice I give to patients surrounding diet revolves around many of the same reasons and principles why women with PCOS are put on metformin. Therefore, I thought it would be beneficial to discuss the basics of metformin and how it can help with insulin resistance, decreasing your testosterone, improving your chances of ovulation, enhancing fertility and you guessed it – weight loss!


What the heck is metformin? 


Metformin is an insulin-sensitizing agent. What this means is metformin makes your body more sensitive to the effects of the hormone insulin. But more about that later!

Metformin comes in tablet form and the dose is gradually increased until the maximum dose required is achieved. Most women with PCOS start at a dose of 500 mg and increase their dose up to 1500 – 2000 mg usually in a 4-6 week span.


 Metformin does the following:

  1. inhibits liver production of glucose
  2. increases the uptake of glucose by the cells
  3. decreases oxidation of fatty acids
  4. decreases the absorption of glucose in the intestines


 Note: Metformin is the most commonly prescribed drug for diabetes.


I have PCOS, NOT diabetes? So, why did my GYNO prescribe metformin for ME?!?


Around 70- 80 % of women with PCOS experience what is called Insulin Resistance (IR). If you have IR, your body produces enough insulin, but does not effectively use it. Therefore, your body is not sensitive to the effects of insulin. Your doctor prescribed metformin to help your body respond better to insulin.



Why is insulin SO dang important?


Insulin plays a critical role in metabolism—the way the body uses food for energy. When you eat, the digestive system breaks down carbohydrates—sugars and starches found in many foods—into glucose. Glucose is a form of sugar that enters the bloodstream. With the help of insulin, glucose gets processed into the cells where it is used for energy.



What is Insulin’s Role in Blood Glucose Control?


When blood glucose levels rise after we eat, the pancreas releases insulin into the blood. Insulin and glucose then travel in the blood to the cells throughout the body.



faviconInsulin plays three key roles in the body- 1. Allows muscle, fat, and liver cells to absorb glucose from the bloodstream. This helps lower blood glucose level 2. Stimulates the liver and muscle tissue to store excess glucose. The stored for



In a healthy person, these actions help regulate blood glucose to keep insulin levels within a normal range.


But I already told you, my doc told me I am NOT healthy! I have PCOS AND Insulin Resistance SO what does that mean?


When someone has insulin resistance their muscle, fat, and liver cells do not respond properly to insulin. Their bodies cannot easily absorb glucose from the bloodstream. As a result, the body needs higher levels of insulin to help glucose enter cells. Basically the cells, despite the presence of insulin in the bloodstream, don’t function properly and don’t allow the glucose in the blood into the cells.


What Role does Insulin Resistance play in PCOS and Weight Loss ?


Insulin is considered a storage hormone. When insulin levels are high (as they are in most women when they are diagnosed with PCOS), the body goes into storage mode. This means the body stores glucose as body fat instead of using it for fuel.


And guess what? What do you think has one of the biggest affects on raising insulin levels? Carbohydrates – especially the refined types! Eating substantial amounts of processed carbohydrates creates large spikes in insulin levels. For women with PCOS – this is like pouring salt on an open wound. No bueno amiga!


As you know, many women who have PCOS are already overweight and carry a substantial amount of body fat in their belly area. Elevated weight and belly fat can further increase IR. Therefore, it no surprise that women who have PCOS have a hard time losing weight – even if their diet and exercise are “spot on.” Insulin resistance and excess weight creates a vicious cycle of weight gain in women with PCOS. And for some – without metformin – this weight is increasingly difficult to take off.


As if that was not bad enough! IR also increases testosterone levels, disrupts menstrual cycles and decreases a women chance of fertility.


How Does Metformin Benefit Women with PCOS?


Metformin is a super hero in my book for women who have PCOS and IR!


Metformin has been used off label in PCOS to prevent diabetes and increase ovulation through weight loss (1). In a recent randomized controlled trial comparing metformin, oral contraceptive pills (OCPs), and the combination of the two in patients with PCOS without T2D, metformin alone or with OCPs decreased weight and BMI. The median decrease in weight with metformin at 12 months was 3 kg (25th and 75th quartiles; -10.3, 0.6). OCP use was associated with increased weight changes of 1.2 kg (25th and 75th quartiles; -0.8, 3.0), and the combination decreased weight by 1.9 kg (25th and 75th quartiles; -4.9, 0.1). One patient in the metformin group dropped out due to nausea; no other side effects or adverse events were reported (2). Therefore, by using metformin by itself or in conjunction with OCPs, women with PCOS experienced a significant decrease in weight over the course of one year.


benefits metformin

Metformin is also likely to delay diabetes onset and has a role in PCOS in those at high risk of diabetes. Boom!


While I do not think it is a miracle drug by any means, I personally have seen many of the positive outcomes I described above in my patients. However, with that being said, these same patients are also strongly adhering to my dietary and exercise advice AND are compliant with taking their metformin. You cannot have one – without the other!


Therefore for many women who have PCOS, taking metformin should be a no brainer due its profound impact on metabolic and reproductive function.


experiences metformin


Support for women with PCOS

Amy Plano PCOS Dietitian






  1. Nieuwenhuis-Ruifrok AE, Kuchenbecker WK, Hoek A, Middleton P, Norman RJ. Insulin sensitizing drugs for weight loss in women of reproductive age who are overweight or obese: systematic review and meta-analysis. Hum Reprod Update. 2009;15:57-68
  2. Glintborg D, Altinok ML, Mumm H, Hermann AP, Ravn P, Andersen M. Body composition is improved during 12 months’ treatment with metformin alone or combined with oral contraceptives compared with treatment with oral contraceptives in polycystic ovary syndrome. J Clin Endocrinol Metab. 2014;99:2584-2591.